This invention relates generally to a cable anchorage for a bridge construction, and more particularly to such an anchorage which facilitates the tensioning of the cable extending through a structural bridge component such as a cantilevered segment of a cable-stayed girder bridge.
The deck girder of such a cable-stayed girder bridge is sequentially constructed as successive adjacent deck sections are cantilevered from previously supported sections. A movable form carrier may be utilized for supporting each successive deck section during its formation. The bridge is supported from pylons or towers extending upwardly from the bridge piers, and straight cables extend obliquely from the pylons to longitudinal stiffening girders of the deck girder sections. The cables lie in vertical or inclined planes along opposing side edges of the deck girder, or in a single vertical plane along the longitudinal axis of the bridge. The ends of the cables are anchored to the stiffening girders, and are tensioned prior to the formation of each successive deck section.
Otherwise, the deck girder sections may be precast and transported to the bridge site. The cable stays are likewise anchored in place.
Thus, after the tension members of the cable, comprising a plurality of strands, tendons, wires or the like, are stressed, and restressing thereof due to subsequent changes in stressing requirements, is difficult to carry out at the anchorage block end. Cable restressing may be carried out at the tower end of the cable, but is tedious and time-consuming leading to long bridge use downtimes which present unbearable problems. Besides, it is impractical and unduly burdensome to easily replace cable stays when the need arises.